1. Field of the Invention
This invention relates to climbing aids, particularly for rock climbing and mountain climbing. More particularly still, the present invention relates to adjustable pitons or climbing chocks having adjustable wedge-type expansible heads that can be inserted into a prepared or otherwise suitable orifice in a rock face to secure a climber against falling, but which can then be easily removed when no longer required and used again in a different suitable orifice. Use of the invention avoids leaving disfiguring pitons or chocks in a rock face where they may corrode, causing unsightly conditions plus possible serious deterioration of the piton itself over a period of time, rendering it unreliable or dangerous to use.
2. Description of the Prior Art
Sport-type mountain climbing, and particularly rock climbing, where the climber attempts to climb relatively sheer rock faces by different routes and techniques, often in an expedition or climbing party lasting only a day, or even less than a day, has burgeoned in recent years to the extent that it is sometimes difficult to even gain access to a desired rock face on a desired day.
Rock climbers rely on the use of safety or climbing ropes removably secured to a face at points selected by the climber or dictated by technique. The ropes have in the past been customarily secured to a rock face by so-called pitons and/or rock bolts which are driven into the rock face, either into preexisting cracks or the like or, in more recent years, into especially prepared openings or orifices made in the rock face by various techniques or tools. The safety ropes are then attached to such pitons and rock bolts in order to belay the climber or climbers against sudden falls or sometimes to aid such climbers in movement from place to place upon the rock face.
The traditional use of steel pitons has the serious disadvantage of leaving such pitons in the crack or other opening once placed, where they inevitably corrode, staining the surrounding rocks, with resulting serious aesthetic problems and causing serious criticism of climbers by other users of the mountains. Environmentalists and conservationists are invariably offended by the sight of multiple pitons and rock bolts, or expansion bolts, used for belaying the ropes of climbers. There are said to be as many as 7,000 fixed anchors, including pitons and expansion or rock bolts, in California's Yosemite and as many as 5,000 in California's Joshua Tree Park alone. These so-called fixed anchors are not only often offensive in themselves to nature and wilderness lovers because they remind one of the intrusion of human technology into wilderness or scenic areas, but, as noted above, their corrosion may leave large stains on the rocks, considerably deteriorating the aesthetic or scenic values for all observers and substantially impossible to remove from the rock face itself.
In recent years there has been an increasing demand by non-climbers that climbers be banned from public rock faces or at least stringently restricted with respect to where and how they can climb. Such restrictions are dictated not so much by safety considerations, but by aesthetic and environmental considerations. Laws have been proposed and regulations by both federal and state park authorities have been proposed and sometimes implemented to regulate and at times ban completely climbers on park lands.
In an attempt to decrease the degradation or outright destruction of the environment by the use of pitons and expansible or other rock bolts in rock faces, environmentally attuned climbers have in more recent years introduced the use of removable and reusable climbing aids in order to make so-called "clean climbs". Most of these devices have involved the use of expansible cam-type chocks in cracks and other openings in rock faces. Exemplary of this type of device is the so-called "Friend" climbing aid, a rotatable cam-type chock described in U.S. Pat. No. 4,184,657. This patented chock is often usable only in fairly large cracks. Another type of device more recently introduced is the flexible expansible head-type device described in U.S. Pat. No. 4,572,464. This device uses two dovetailed wedge-type heads attached to the ends of flexible wire strands which are used to facilitate insertion of such wedge-type heads into cracks and the like. While these devices have proved effective within their intended scope of use, they have not completely solved the above referred to environmental and aesthetic problems and, in fact, have at times exhibited poor attachment to the rock faces or have been difficult to remove, even though removal is supposed to be their principal advantage. Several other similar devices have been designed to remedy the basic disadvantages of the original device, disclosed in the '464 patent. For example, improvements are disclosed in U.S. Pat. Nos. 4,643,378, 4,715,568 and 4,834,327, which improved devices have each added to the flexibility of the basic device, particularly for use in cracks and the like. However, the use of such improved devices has also sometimes been less than satisfactory.
In particular, there has been a need for a removable piton or rock bolt-type device which can always gain a good grip within an orifice and can always be relatively easily removed so that it is not left on the rock face to corrode. There has also been a need for a removable piton that can be effectively used in prepared orifices which have a minimal environmental or aesthetic impact.